The present invention relates to a video processing apparatus and method and, more particularly, to such apparatus and method for use with an electronic still camera for recording and/or reproducing still image digital video signals onto and/or from a recording medium such as an optical disk, a magneto-optical disk or a semiconductor memory.
In a digital recording type electronic still camera, an image of an object may be supplied through a photographing or charge coupled device (CCD) so as to obtain a video signal. Such video signal may be converted to digital form and compressed in accordance with an image compression technique of the Joint Photographic Experts Group (JPEG). The JPEG technique may compress still image data by using a discrete cosine transform (DCT) and length-variable coding. As a result, such JPEG technique may be able to compress colored still image data with a relatively high compression ratio, such as 1 to 1/100. The digital compressed video signal may thereafter be recorded on a recording medium.
The recording medium may be a magneto-optical disk which is contained in a housing or cartridge. Such magneto-optical disk may have an outer diameter of approximately 64 mm and a thickness of approximately 1.2 millimeters. Further, such magneto-optical disk may have a plurality of tracks for storing data with a track pitch of approximately 1.6 micrometers.
The above-described magneto-optical disk/cartridge may be similar to a so-called mini-disk (MD) used to record audio data. Such disk may record approximately 140 Mbytes of data, which corresponds to approximately 365 still pictures in JPEG-compressed form and approximately 40 minutes of audio information in a so-called ATRAC (Adaptive Transform Acoustic Coding) form.
The above-described electronic still camera which records data in a digital form onto a magneto-optical disk has numerous advantages. For example, a relatively large number of still image data may be recorded on one disk, the quality of the recorded images may remain substantially high and may not substantially deteriorate over time, compilation of data is relatively easy, and still image data may be copied into a computer. Furthermore, such use is believed to increase in the future.
Electronic still cameras, such as that described above which records a still image of an object in digital form on a magneto-optical disk, and other electronic still cameras, such as those which record a still image of an object in analog form on a magneto-optical disk, use optical view finders. Such optical view finders may be difficult for an inexperienced operator to use because the entire image of an object to be photographed may be difficult to comprehend. Additionally, an image photographed through an optical view finder may not be reproduced thereat (in situ). These difficulties or drawbacks may be overcome by using an electronic view finder, such as that illustrated in FIG. 10. Such electronic view finder may display the image to be photographed; characters 102 which may indicate the current state of operation, place and date of the photograph; and patterns 101 of a frame or ornamentation for the display. Numerous patterns or characters may be available for display. Such patterns and/or characters may be generated or provided from a read only memory (ROM). Desired pattern(s) and/or character(s) from the ROM may be incorporated or combined into video image signals and the combined video image/pattern/character signals may be stored in an image memory.
The above-described technique of combining pattern and character signals from a ROM and storing the combined signal in an image memory may have several disadvantages. For example, information or data pertaining to the image of the original photograph in the image memory may be lost. Additionally, utilizing a ROM to provide patterns or characters on a screen may require an exclusive or dedicated ROM and, as such, may increase the scale or complexity of the circuit and the cost thereof.